OF MENTAL AND MECHANICAL WORK. 141 



we know, cannot possiby be fulfilled, and therefore no true 

 analogy can exist between any machines made by us and 

 the nervous mechanism concerned in mental action. But 

 admitting that they might be, and without laying stress 

 upon the fact that the nervous apparatus, unlike the machine, 

 keeps itself in order and in working condition if only the 

 rest needful for its repair and renovation be granted, we 

 have yet to find the power, the hand that guides the mental 

 engine, its superintendent, who bids the wheels revolve or 

 stops them, who allows the work to proceed or checks it, as 

 he wills. What sort of guide can we find in the case of the 

 mental machine, where is he seated, and how does he 

 influence the complex apparatus under his immediate indi- 

 vidual care and sole control ? In what spot in the brain 

 are we to search for him ? But do we not know that the 

 structure of the grey matter is such as to preclude the 

 possibility of the existence of anything exhibiting any 

 approach towards any mechanical arrangements known ? 

 We understand its construction sufficiently to justify us in 

 concluding that the nervous matter operates in a manner 

 different in principle from the action of any known me- 

 chanism. 



It has been said that in the brain we have " molecular 

 machinery" built by the sun, but no one has shown what 

 this supposed molecular machinery is like, what is its 

 structure, how it acts, or how it is formed. Molecular 

 machinery is a term which conveys no idea whatever to the 

 mind. No one could draw or make a model of the supposed 

 molecular machinery. We may have molecular matter, and 

 we may have machinery, but there are no machines the 



